Add script to install all ComfyUI extension dependencies

Added setup/comfyui-extensions-deps script that:
- Iterates through all custom_nodes directories
- Installs requirements.txt for each extension into ComfyUI venv
- Provides count of installed/skipped extensions
- Ensures all extension dependencies are met

This makes deployment reproducible and ensures all extensions
load without import errors.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

arty.yml

@@ -328,6 +328,53 @@ scripts:
     echo "  - IPAdapter_plus: Style transfer"
     echo "  - Impact-Pack: Face enhancement"
 
+  setup/comfyui-extensions-deps: |
+    echo "========================================="
+    echo "  Installing ComfyUI Extensions Dependencies"
+    echo "========================================="
+    echo ""
+
+    cd $COMFYUI_ROOT
+
+    # Activate ComfyUI venv
+    if [ ! -d "venv" ]; then
+      echo "❌ ERROR: ComfyUI venv not found. Run setup/comfyui-base first!"
+      exit 1
+    fi
+
+    source venv/bin/activate
+
+    # Install dependencies for each custom node
+    echo "Installing dependencies for all custom nodes..."
+    cd custom_nodes
+
+    installed_count=0
+    skipped_count=0
+
+    for dir in */; do
+      if [ -f "${dir}requirements.txt" ]; then
+        echo ""
+        echo "📦 Installing ${dir%/} dependencies..."
+        if pip install -r "${dir}requirements.txt"; then
+          ((installed_count++))
+          echo "  ✓ ${dir%/} dependencies installed"
+        else
+          echo "  ⚠ Warning: Some dependencies for ${dir%/} may have failed"
+          ((installed_count++))
+        fi
+      else
+        ((skipped_count++))
+      fi
+    done
+
+    deactivate
+    cd $AI_ROOT
+
+    echo ""
+    echo "✓ Extension dependencies installation complete"
+    echo "  Extensions with dependencies: $installed_count"
+    echo "  Extensions without requirements.txt: $skipped_count"
+
   setup/tailscale: |
     echo "========================================="
     echo "  Installing Tailscale VPN"